Conventionally, a semiconductor dynamic quantity sensor has been proposed which has a movable portion with a beam-like structure and a fixed portion, and detects a dynamic quantity such as an acceleration, a yaw rate, vibration, or the like by detecting, e.g., a change in the capacitance between the movable portion and the fixed portion (see, e.g., Patent Documents 1 to 3). In each of Documents 1 to 3, a semiconductor dynamic quantity sensor is shown in which a movable portion with a beam-like structure and a fixed portion, each functioning as a sensing portion, are formed on a multilayer SOI substrate, and wiring connecting the individual portions is made of polysilicon or the like.
In Patent Document 4, a semiconductor dynamic quantity sensor is proposed which can prevent the entrance of water or a foreign substance into a movable portion by covering the movable portion with a cap member. In the semiconductor dynamic quantity sensor shown in Patent Document 4, the cap member is provided with a large number of through holes, and wire bonding is performed directly to wire bonding pads provided on an SOI substrate formed with the movable portion and a fixed portion, so that the wires are used as a replacement for a wiring layer.
In Patent Document 5, a semiconductor dynamic quantity sensor is proposed which has a structure obtained by laminating, on a silicon layer composing an SOI substrate and provided with a movable portion or the like, a silicon layer composing another SOI substrate and provided with a signal processing circuit via an annular bump. In Patent Document 6, another example of the annular bump is proposed. In a sensor having such a structure, a wiring layer is provided from a signal processing circuit to electrically connect the signal processing circuit and the outside, and the wiring layer is extracted crosswise to the outside of the annular bump, while it is insulated from the annular bump.
Patent Document 1: JP-H9-129898 A
Patent Document 2: JP-H11-295336 A
Patent Document 3: JP-H6-123628 A
Patent Document 4: JP-2004-333133 A
Patent Document 5: JP-2004-311951 A
Patent Document 6: JP-H11-94506 A
However, each of the technologies described in Patent Documents 1 to 3 has the problem that, since the wiring layer made of a polysilicon layer is formed on the same substrate formed with the sensing portion, the manufacturing process is complicated, and the yield of the manufactured semiconductor dynamic quantity sensor lowers.
With the technology described in Patent Document 4, it is necessary to form the large number of holes extending through the cap member. Moreover, since the bonding wires are connected to the wire bonding pads using a bonding tool, the large-sized through holes should be formed to keep the tool from contact with the sidewall surfaces of the through holes. This leads to the problem that a semiconductor chip formed with the semiconductor dynamic quantity sensor has a large chip size.
With the technology described in Patent Document 5, since the wiring layer crosses the annular bump, the bump and the wiring layer should be isolated with an insulator layer to be electrically insulated from each other. This leads to the problem that the structure of the semiconductor dynamic quantity sensor is complicated.
Thus, it is required to simplify the structure of a sensor in a semiconductor device, and to reduce a chip size.